We repeat that when not endowed with speech, or some analogous means, animals and man think in images, and the relations between these images are observed in the simultaneousness and succession of their real differences; these images are combined, associated, and compared by the development of reflex power, and hence arises the estimate of their concrete relations. Of this we have another proof, observed by Romanes in a lecture on the intelligence of animals, and confirmed by myself, in the condition of deaf-mutes before they are educated, in whose case the extrinsic sign and figure takes the place of the phonetic and articulate sign. Where speech is wanting, it is still possible to follow a conscious and imaginative process of reasoning, but not to rise to the higher abstract ideas which may be generated by such reasoning. The thought of deaf-mutes always assumes the most concrete form, and one who was educated late in life informed Romanes that he had always before thought in images. I know no instance of a deaf-mute who has independently attained to an advanced intellectual stage, or who has been able without education to form any conception of a supernatural world. R.S. Smith asserts that one of his deaf-mute pupils believed, before his education, that the Bible had been printed in the heavens by a printing press of enormous power; and Graham Bell speaks of a deaf-mute who supposed that people went to church to do honour to the clergyman. In short, the intellectual condition of uneducated deaf-mutes is on a level with that of animals, as far as the possibility of forming abstract ideas is concerned, and they think in images. There is a well-known instance in the deplorable condition of Laura Bridgman, who from the time she was two years old, was deaf and dumb, blind, and even without the sense of taste, so that the sense of touch was all that remained. By persevering and tender instruction, she attained to an intellectual condition which was relatively high. A careful study of her case showed that she had been altogether without intuitive knowledge of causes, of the absolute, and of God. Howe doubts whether she had any idea of space and time, but this was not absolutely proved, since as far as distance was concerned, she seemed to estimate it, by muscular sensation. Everything showed that she thought in images. Although without any sensation of light or sound, she made certain noises in her throat to indicate different people when she was conscious of their presence or when she thought of them, so that she was naturally impelled to express every thought or sensation, not externally perceived, by a sign; and this shows the tendency of every idea and image towards an extrinsic form. She often conversed with herself, generally making signs with one hand and replying with the other. It was evident that a muscular sign or the motion of the fingers was substituted for the phonetic signs of speech, and in this way ideas and images received